Fuse plug and socket



July 5, 1927. 1,634,905

C. B. JONES FUSE PLUG AND SOCKET Filed March 29. 1921 HHHHHHl 46 1,HHH-- Z5 il,

Patented July 5, 1927.

UNITED STATES PATENT OFFICE.

` CHARLES BROOKE JOES, OF ABOVE CYNWYD, PENNSYLVANIA.

FUSE PLUG AND SOCKET.

Application led March 29, 1921. Serial No. 456,599.

" ing fuse socket free from other contacts than holding mechanism and to retain the fuse in position by the contacts.`

A further purpose is 'to form laterally projecting contact members at the lower end. of a fuse and engage them -with cooperatmg contact devices beneath the fuse socket and acting as retaining devices only.

A further purpose is 'to locate a fuseblock ada ted for retention by the Contact devices. so t at it will turn in the direction of engagement only.

Further purposes will appear in the speciiication and in -the claims.

I have preferred to illustrate my invention by but one general form, selecting a form which is practical, eliicient, thoroughly reli-` able and relatively inexpensive and which at the same time well illustrates the principles of my invention.

Figure 1 is a perspective of the preferred form of a plug and socket embodying my invention in assembled position.

Figure 2 isa top plan view of the structure seen 'in Figure 1.

Figure 3 is a section upon line 3 3 of Figure 4, showing a bottom plan view of part of the structure.

Figure 4 is a section upon line 4-4 of Figure 3.

Figures 5 and 6 are sections upon lrnes 5-5 and GMG of Figure 2.

Figure is a section upon line 7-7 kof Figure 3.

Figure 8 is a central vertical section in perspective of the `fuse plug seen in the other figures.

Figure 9 is a section corresponding to Figure 4 showing a Jfuse plugr and socket of the same type but of different capacity.

In the drawing similar numerals indicate like parts.

All of those familiar with' existing commercial incandescent light and small capacity power circuits recognize the objection to interchangeable fuses whereby` afuse of almost any capacity may be inserted within a circuit which has been designed and wired for a low current only.

"For example, house circuits designed to carry a very low current only, too frequently carry as high a current: as the main house fuses will stand, because of a shift in fuses made by the householder without consulting the electrician or any authorities who should control. My invention has been directed in part to prevention of such interchangiug of fuses and in the hope that cooperation with the underwriters with respect to a new fuse will make it possible to prevent such substitution of improper sizes of fuses. However, most of the features of my invention are suitable for fuse Work generally, whether lthe distinction between different sizes of fuses be maintained or not.

My fuse construction contemplates a special fuse socket member 10 and cooperating fuse plug 11. The socket member comprises an upper block 12 and a cover plate 13. The block consists of a relatively liat body member 14 and an upwardly extending cylindrical shell l5. The body is recessed toward the ends from the middle to form a space 16. between it and the protecting plate` which space is bounded by 'the wall 17. The interior of the block forms a barrel .tor the plug. presenting an interior cylindrical surface 1S. This barrel is axially grooved at the sides to form slots 19 and 20 which bottom at 21 and 22.

Two pairs of contacts 23, 23 and 24, 24 are located one pair at each end or side of the plug. They are bent to a general Z shape in order to facilitate their anchorage within the block. These contacts are passed through or cast into the porcelain or other insulating materiai of 'the biocks and their actual engaging portions are in the form of mating pairs or' wiping plates 25. 25 and 26, 26.

At their upper ends these contacts extend L and are held in position by screws 30 inserted from the bottom to avoid interference with or accidental release ot the contacts. Piniling screws 31 also connect the plates and pass through openings 32 in the blocks.

The lower of the wiping plates should be of spring metal and the two ot the pair should be separated at the ends to provide for insertion of the contacts carried by the plug. I lind tliat it is desirable to recess the under-side of the block additionally at 33, 34 to provide spaces for movement of the plug contacts, and to still further recess the block at 35 for the upper plates, so that the lower faces of the upper contact plates shall be level with the bottom of the recesses 33, 34 which will then uide the plug contacts between the pairs ot wiping contact plates.

The block 12 and cover plate 13 are held together by bolts passing through the openings 36 and inserted from the top.

oth the cover or facing plate 13 and the block are held to the support by bolts 3T passin downwardly through them.

Wit in the socket thus provided I apply the plug 11 having a barrel structure corresponding generally to the interior bai'rel of the socket. The contact members 3S, 39 are preferably cast within it, with portions 40 and 41 embedded in the porcelain and with their upper portions turned toward cach other as at 42 within a recess 43 so that the fuse'44 may be secured across them.

The upper end of the plug is ilanged at 45 and carries an annular, preferably knurled ring 46 by which the mica cover 47 is held in place. The plug is extended axially at the bottom at 48, so as to rest upon the plate 13 to form a stop, in such position that the laterally projecting ends or fingers 49, 50 of contact members 38, 39 wipe contact pairs 25, 25 and 26, 26 when the block is given a partial turn. Though the block is free to turn to the left in Fiigure 3 (to the right in Figure 1) to cause engagement of the parts, it is not free to turn in the reverse direction because of flanges 51 which form stops to prevent reverse movement of fingers 49 and 50.

I prefer to make the sockets of standard external size, the saine for a considerable range of fuse sizes, but to make the bores at 18 diderent-for dii'erent sizes, so that a smaller fuse, Jfor example, such as shown in Figure 9 shall have a smaller bore 18 in its socket and a smaller diameter plug, to prevent replacement by a larger fuse. The distance between the fingers 49 on one side and 50 on the opposite side is preferably varied with the size of bore, so as not to require an excessive projection ot the fingers for the larger sizes.

It will be obvious that my disclosure herein will suggest other forms than those here illustrated and that the skill of those working in the art as well as the whim or preference of the designer and the particular needs he has in mind will result in many changes. I purpose including herein all such as fall within the reasonable spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a fuse plug and socket, the combina tion of a base having a bore and grooves in communication with the bore, the base being recessed about the bore, contacts within the base at a greater distance from the center than the bore and passing through the base, binding posts on the upper side of the base engaging said contacts, a plug having a diameter corresponding to the bore, contacts carried by the plug adapted to fit within the grooves and engage with the iirst named contacts and a stop limiting the insertion ot the plug to bring the contacts in line for engageinent.

2. In a fuse plug and socket, a socket having a bore and an upper member recessed in the lower portion, a closing plate attached thereto, a pair of horizontally extending contact lingers on each side of the socket within the recess, a plug adapted to Iit the bore, contacts thereon extending laterally at .their outer ends at its lower end and at their inner ends upwardly therefrom within the plug to a. recess in the plug and a fuse joining the upper ends of the contacts.

3. In a fuse plug and socket, a body having an upper member recessed in the lower portion, a closing plate attached thereto to forni a bottoni, a pair of horizontally extending contact fingers on each side of the Jfuse body within the recess, a plug adapted to fit the bore and its end bottoniiiig on the closingl plate, contacts extending horizontally therefrom within the plug to a recess in the plug and a fuse joining the upper ends of the contacts.

4. A fuse pluff comprising approximately cylindrical sidesbhaving a recess in the u per portion, a transparent closure for sait recess, contacts embedded in the plug, extending laterally from the lower parts of the sides and upwardly within the body of the plug and terminating in the recess and a fuse joining the upper ends of the contacts.

5. A fuse socket comprising an upper member having a bore, grooves in communication with the bore, recessed in the lower part and additionally recessed in one direction of plug rotation adjacent the grooves, affording a sto against plug rotation in the opposite direction, contacts lying within the additionally recessed portion, binding posts connected with said contacts, accessible upon the upper surface of the socket and a closure plate for said recess in the lower part of the socket.

6. A socket body having a bore and a recess in the lower part of the body and grooved in communication therewith, a pair of contact plates extending along the surface of the body, passing downwardly` through the body and extending into the recess, adjacent t e bore, a retaining screw for said plates accessible from within the recess and holding the plates together outside the body, a binding post engaging one of the plates and a closure for the bottom recess.

7 In a fuse socket, a body portion having a -bore and grooves in con'nnunication with the bore and having a recess in the bottom and an additional recess communicating therewith adjacent the grooves in one direction of plug rotation and atl'ording a stopy in the opposite direction thereof, a pair of contact plates in each additional recess extending upwardly through the body and terminating above the body and a closure for the bottom recess.

8. In a fuse plug and socket, a fuse plug having a straight cylindrical body, a fuse within a recess in the upper (part of the body and contact strips connecte with the ends of the fuse, tightly embedded in the material of the -body and extending laterally from the body and a socket havmg a bore corresponding to the cylindrical plug and grooved adjacent thereto/ for entry of the contacts, in combination with cooperating contacts within thesocket.

9. In a fuse plug and socket, a fuse plug having a straight cylindrical body, a fuse within a recess 1n the upper art of the body and contact stri s connecte with the ends of the fuse, tig tly embedded in the material of the body and extending laterally from the body and a socket having a bore corresponding to the cylindrical plug and grooved adjacent thereto for entry of the contacts, in combination with cooperating contacts within the socket, providing for engagement with one direction of plug rotation, and stops preventing reverse rotation of the plug.

10. In a fuse plug and socket, a fuse plug having a straight cylindrical body, a fuse within a recess in the upper art of the body and contact strips connected with the ends of the fuse, embedded in the body and extending laterally from the body and a socket having a bore correspondin to the cylindrical plug and grooved a jacent thereto for entry of the contacts, in combination with cooperating contacts within the socket, providing for engagement with one direction of plug rotation, and stops preventing reverse rotation of the plug, and a bottom plate against which the end of the plug abuts to limit the plug insertion.

11. In a fuse plug and socket, a fuse plug having a straight cylindrical body, laterally extending contacts near the bottom of the body and a projection below the contacts, in combination with a socket having a bore correspondin to the body, laterally grooved adjacent t e bore and extending below the bottom of the bore, contacts adapted to be engaged by the contacts of the plug and a bottom closure acting as a stop to the said projection.

12. A fuse socket having a longitudinal bore grooved at the sides and a counterbore at one end thereof, vertically spaced pairs of contacts on opposite sides of the bore in the counterbore affording wiping contact and plug for the socket having laterally extendlng contacts adapted to pass into the space beeween the contacts of 'the bores into wiping engagement with them.

13. A socket having a longitudinally grooved bore and a counterbore at one end thereof, a pair of vertically spaced engaging contact strips on` each side entering the counterbore and extending outside of the socket for electrical connection therewith, a fuse plug fitting the bore, a fuse within the plug and contacts connected with the fuse within the plug and extending lon itudinally of the plug and then latera ly thereto and adapted to engage the contact within the bores.

CHARLES BROOKE JONES 

